28 Ways Chevrolet Camaro Z/28 Rules the Road Course

DETROIT--Feb. 17, 2014: Lightweight, nimble and incredibly powerful, the
original Z/28 was designed for road racing. The 2014 Z/28 carries the same
spirit, with every detail engineered specifically to create the ultimate
track-capable Camaro.

To enable the Z/28 to quickly lap the most challenging road courses,
engineers and designers focused on strengthening three key areas during
development:

To enhance the balance and overall driving feel of the Z/28, 100 percent
of the unsprung mass – suspension, wheels, tires and brake system
– differs from the Camaro SS.

“Like the first-generation Z/28, the new model is a road racer
first and foremost. It features a wide range of state-of-the-art exterior
performance modifications, and weight-reduction measures. It was bred for
the track, pure and simple,” said Mark Stielow, Camaro Z/28
engineering manager.

Exterior Design and Aerodynamics

With the driving goal focused on peak performance capability, nothing on
the exterior is without purpose. It shares several racing-inspired, design
best practices and lessons learned with the 2014 Corvette Stingray. New and
revised exterior content was developed to improve aerodynamics, powertrain
cooling and brake-system cooling, helping the Z/28 produce 150 pounds of
downforce at 150 mph.

Here are 28 features that helped the Camaro Z/28 lap Germany’s
famous Nürburgring road course four seconds faster than the Camaro ZL1.

1. Rear spoiler with ‘wickerbill’

The aerodynamic coefficient of drag goal was achieved with original
Camaro SS content and an accessory rear spoiler, but to meet the downforce
requirements for Z/28, the spoiler was modified with a
“wickerbill” – a small, vertical tab at the edge of the
spoiler. Although an aesthetically minor change, it helped improve rear
lift performance by 70 counts. That allows the Z/28 to handle turns at
higher speeds and deliver greater overall high-speed stability.

2. Unique front fascia

The Z/28’s unique front fascia is based on the Camaro SS, but the
fog lamps, air dam and the upper-base grille are replaced with covers that
reduce weight from deleting fog lamps, an air duct support bracket, an
airflow-optimized grille for enhanced cooling and a modified fascia bottom
that incorporates provisions for the brake cooling ducts. They funnel air
from the lower grille to the wheelhouse liners and the unique splitter.

3. Front splitter

The Z/28’s front splitter is a large aero panel that provides
downforce at the front of the car, enhancing cornering capability and
high-speed stability. Designed to withstand 250 pounds of downforce at its
tip, it is matched with an aero closeout panel under the front of the
engine compartment that also enhances aero characteristics – along
with molded-in aero features forward of the front wheels.

4. Hood extractor

A functional carbon fiber hood extractor provides increased engine
cooling by allowing hot air an exit route. The design is similar in
function to the extractor featured on the Camaro ZL1.

Unique wheelhouse liners with closeouts work with the vehicle underbody
to make the most of airflow.

7. Belly pan

The Z/28 underbody incorporates a belly pan that helps reduce front
lift. Developed using computational fluid dynamics and wind-tunnel testing.
It provides an aero benefit and contributes to drivetrain cooling. Modified
NACA duct profiles are designed to draw air into the underbody tunnel area,
where the highly energized air provides extra cooling for underbody
components affected by the exhaust heat energy of the LS7 engine.

Weight Reduction

Making the most of mass is a key component of the Z/28’s
performance capability, contributing to a balanced feel and a high
power-to-weight ratio. With a curb weight of 3,820 pounds and 505
horsepower (376 kW), the Z/28 has a power-to-weight ratio of 7.6:1 –
or one horsepower for every 7.6 pounds of the car’s mass. That
compares favorably to other performance coupes, including Audi RS 5
(8.9:1), BMW M3 (8.9:1) and Porsche 911 Carrera (8.7:1).

The Z/28’s curb weight is approximately 300 pounds less than the
ZL1 and about 55 pounds less the 1LE, despite features that add mass,
including a dry-sump oiling system with a 10.5-quart reservoir, higher-mass
chassis and suspension components such as the support brackets for the
front splitter. Engineers offset the mass of those necessary features with
a targeted weight-loss program that trimmed the Z/28 to the essential
elements of performance.

Although it looks like the rear seat in the SS, the Z/28’s rear
seat is 4.7 kilograms lighter due to reduced seat foam and a fixed seatback
design with no folding/pass-through feature.

10. Lightweight wheels and tires

The Z/28’s 19-inch aluminum wheels save 8.7 kilograms compared to
Camaro SS wheels. Their thin split-spoke design features a back-cut at the
rim, reducing mass at the outermost area of the wheel – and reducing
spin inertia by 5 percent, for enhanced performance. They are matched with
track-capable tires that save 13.2 kilograms per vehicle, compared to the
SS.

Because the Z/28 is intended for the track, air conditioning was deemed
non-essential component. The deletion saved 12.9 kilograms. Air
conditioning is available as an option.

Powertrain

The Camaro Z/28’s powertrain is rooted in the 7.0L LS7 engine that
made the Corvette Z06 an instant performance icon. With an SAE-certified
505 horsepower (376 kW) and 481 lb-ft of torque (652 Nm), it complements
the lightweight vehicle components to give the car its 7.6:1
power-to-weight ratio while delivering the power to accelerate strongly out
of corners and achieve high straightaway speeds.

A close-ratio six-speed manual transmission is the only transmission
offered and power is distributed to the rear wheels via a limited-slip
differential featuring a helical gear set, rather than traditional clutch
packs. The new design enables the driver to apply more power and get
through corners faster, by continuously adjusting the torque bias to
maximize available traction.

The differential works in unison with Chevrolet’s proprietary
Performance Traction Management system, which allows drivers to adjust the
level of throttle and brake intervention to match their capability and
driving environment.

13. LS7 engine with dry-sump oiling

The racetrack-bred LS7includes features designed for the high-rpm
environment of the track, including a durable forged-steel crankshaft,
lightweight titanium connecting rods and high-flow cylinder heads with
lightweight titanium intake valves. It also features a racing-style
dry-sump oiling system that helps ensure adequate oil pressure during
high-load cornering.

14. Air intake system

The LS7 uses a unique open air box intake system to make the most of
high-rpm airflow into the engine. It features a K&N conical air filter and
delivers the highest airflow performance of any production Camaro filter
system. The air cleaner seals around bottom of the hood, reducing the
chance of recirculated hot air being drawn into the engine.

15. Track-capable fuel system

Engineered to meet the fueling demands of the high-output LS7 engine
during aggressive driving maneuvers, the road course-ready fuel system is
designed to keep the primary fuel pump reservoir full even under hard
cornering and maximize the amount of fuel available during high-performance
maneuvers around the most grueling road courses.

16. Active dual-mode exhaust system and high-flow converter assembly

The 2014 Z/28’s dual-mode exhaust system is engineered to provide
high-flow and muscular sound character under aggressive acceleration, while
attenuating noise levels in cruising conditions. It actively controls
valves that change the flow path of the exhaust for the desired
performance, depending on transmission gear and engine speed. With the
valves open, the system produces less back pressure and more power from the
engine. Additionally, the converter assembly has been modified to increase
flow and horsepower.

17. TREMEC TR6060 six-speed manual transmission

Used in the Camaro ZL1 and Cadillac CTS V-Series, the TREMEC TR6060
six-speed manual has the capability to stand up to high-performance
engines, with short throws, smooth gear synchronization and excellent shift
feel. Design features include a combination of double-cone and triple-cone
synchronizers on all gears. Double-cone synchronizers have two friction
surfaces to affect gear acceleration and triple-cone synchronizers have
three friction surfaces – the greater the friction surface, the
easier the transmission is to shift.

18. 5.1-ratio short-throw shifter

The Z/28 uses a 5.1-ratio short-throw shifter that provides quicker,
more precise-feeling gear changes – similar to ZL1 and SS 1LE
models.

Chassis and Suspension

The Z/28’s performance focus is maximum cornering, braking and lap
times. Comprehensive chassis and suspension changes, including a lower
center of gravity, specific stabilizer bars, higher-rate coil springs and
other chassis and suspension features, enable more than 1.05 g in lateral
acceleration and 1.5 g in deceleration. Racing-bred dampers, tires and
carbon ceramic brakes play important roles in predictable and consistent
maximum performance with every lap.

19. Strut tower brace

The Z/28 uses the same tower strut brace as the Camaro SS 1LE to provide
extra chassis stiffness by tying the towers together. It transmits the load
of each strut tower during cornering via tension and compression of the
strut bar, which shares the load between both towers and reduces chassis
flex.

20. Zero-preload limited-slip differential

A high-performance, zero-preload limited-slip differential is employed
to make the most of cornering capability and cornering exit traction. It
features a concentric helical gear set that generates friction proportional
to the input torque and allows continuous torque biasing and
differentiation to be managed between the drive wheels. A conventional
limited-slip differential uses preloaded clutch plates and springs to
create a fixed amount of friction that is always present).

As torque increases from the engine, the separation forces in the gears
increase to drive increased friction, maximizing the capability of
individual-wheel antilock brake function during corner-entry braking,
mid-corner speed and corner-exit traction. On the track, that translates
into quicker lap times, by allowing the Z/28 to put down more power in the
turns, with greater traction, greater handling precision and enhanced
steering centering. The axle ratio is 3.91.

21. Differential cooler

The Z/28’s differential cooler pulled from the knowledge gained in
developing the ZL1, which is unlike that found in other sports cars. It
incorporates an integral heat exchanger, eliminating the need for an
external pump, wiring, relays, temperature sensors and fan. This innovative
system pumps overcooled transmission fluid to a heat exchanger inside the
differential housing, which removes excess heat from the differential
fluid, reducing temperatures by more than 100 degrees F, helping the
differential maintain cool, stable performance throughout the most
aggressive road course sessions.

22. Uprated lower control arm ride link “travel limiter”
bushing

This higher-durometer part offers 50-percent greater stiffness at high
load than the SS, improving steering feel and brake force deflection steer
while providing more consistent performance for continuous road-course
driving. Additionally, the lower control arm lateral link handling bushing
is revised on all 2014 Camaros for more consistent track performance.

The “P-bracket” bushing for the rear upper control arms is
redesigned with increased durometer and eliminated voids to improve lateral
stiffness during hard cornering, as well as toe-change compliance during
braking. The stiffness rate of this part is increased 400 percent, compared
with the SS component. Similarly, 25-percent stiffer lower inner and outer
trailing links bushings deliver improved lateral stiffness during hard
cornering and reduced toe-change compliance during hard braking.

24. Higher-rate coil springs and smaller-diameter stabilizer bars

Engineers increased the stiffness rate of the Z/28’s coil springs
– the amount of energy required to compress them – by 85
percent in the front and 65 percent in the rear. The specific tuning of the
springs reduces body movement, which allowed the engineers to use smaller,
lighter stabilizer bars to maximize grip during hard braking, cornering and
acceleration. The solid stabilizer bars are 25mm in diameter in the front
and 26mm in the rear – compared to the 28mm front and 27mm solid bars
used on the Camaro SS 1LE.

25. DSSV® damper technology

The Z/28 is the first high-volume production road car to employ
racing-derived DSSV® or Dynamic Suspensions Spool Valve damper technology
from Multimatic. The dampers rely upon a pair of self-piloted spool valves
to control fluid through tuned port shapes rather than conventional
deflected disc dampers. The design of the inverted-monotube front strut and
aluminum-body monotube rear hydraulic dampers offers maximum response,
stiffness and tuning optimized for the track, with the highest level of
damper predictability, accuracy and repeatability. In short, they deliver
optimal wheel control and vehicle control – and they provide almost
double the stiffness when compared to the dampers on the Camaro SS 1LE.

26. Performance Traction Management

Performance Traction Management, or PTM, is an advanced system that
integrates the chassis mode selection, Traction Control and Active Handling
Systems, tuned specifically in the Z/28 for optimal road-course performance
and consistency. PTM allows the driver to press the accelerator pedal to
wide open at the exit of the corner and manages acceleration based on the
given vehicle dynamics. Five performance levels or modes are available to
accommodate a variety of driving conditions.

27. Nineteen-inch wheels and Pirelli PZero Trofeo R tires

A major contributor to the lateral performance of the Z/28 is the
wheel-and-tire combination, featuring the widest front wheels/tires of any
comparable sports coupe. Engineers incorporated a comparatively smaller,
19-inch package, with P305/30/ZR19 tires front and rear – mounted on
19x11-inch front wheels and 19x11.5-inch rear wheels – which
contributed to lowering the center of gravity 33mm, for enhanced handling.
The forged aluminum wheels are lighter and stiffer than comparable SS
wheels, and they’re used with Pirelli PZero Trofeo R motorsport
compound tires. Designed for summer use on the street, the tires’
unique compound was developed for the track and provides a large contact
patch for maximum grip. They also offer a 29.5-pound weight advantage over
Camaro SS tires.